Insulation-stripping mechanism



Aug. 10 1926. 1,595,793

D. LEVINGER ET AL INSULATION STRIPPING MECHANISM Filed Nov. 7. 1921 5Sheets-Sheet 1 Aug. 10 1926. 1,595,793

D. LEVINGER ET AL ,5 [rzflerzZors \g -41; fldfld Lei/492587 ix; ll 7/ @f,W J M Patented Aug. 10, 1926.

UNITED sTATEs 1,595,193 PATENT OFFICE;

navm 'LEVfIIN'GER AND ammo ENGELHABD BALDUF, or CHICAGO, rumors, AS-

sren'ons r wns'rnnn ELECTRIC COMPANY, mconronmrnn, or new YORK, N. "2.,

A CORPORATION OF NEW YORK.

INS'ULATION-STRIPPING MECHANISM.

Application med November 7, 1921 Serial No. 518,828.

This invention relates to mechanism for removing the insulatingcoverings from theends of insulated conductors and has for its objectthe rovision of a simple and convenient mec anism by means of which theinsulating covering may be ra idly and efficiently removed from the en sof conductors without any particular skill or previous training on thepart of the operator. In accordance with the general features of thisinvention, there is provided a mechanism in which a plurality ofsevering members are caused to be engaged with the insulating coveringof a conductor inserted between them'to sever the covering from theconductor upon relative rotation of the severing members and theconductor and to stri the insulation from the conductor upon a re ativelongitudinal movement of the con ductor and the severing elements. Inthe preferred form of the mechanism the severing members areelectrically heated elements, although it will be obvious that theinvention in its broader aspects is not limited to sucl1,elements.

Other features of this invention relate to the construction andcombination of parts which provide for a compact structure adapted to beconveniently mounted upon a work bench with the working parts easilyaccessible for repair and replacement and to the features ofconstruction for roviding for the rem'ovalof the stripped lnsulationfrom the machine.

In the drawings .Fig. 1 is a front elevation of the complete mechanismwith the cover and base member in section and the face plate removed;

Fig. 2 is a vertical section taken om the line 2 2 of Fig. 1 looking inthe direction indicated by the arrows;

Fig. 3 is a fragmentary vertical section taken on the line 33 of Fig. 2looking in the direction indicated by the arrows;

4 Fig. 4 is a section taken on the line 44 of Fig. 3 looking in thedirection indicated by the arrows;

Fig. 5 is a plan view of the complete mechanism with the covers partlyremoved and the face plate in section;

Fig. 6 is a fragmentary front elevation of the mechanism showing theopening in the face plate for the entrance of the conductors;

block 20 by a pin 25.

V Fig. 7 is a dperspective view of the electrically heate blades withtheir supports shown in their operative position with a conductortherebetween, the arrow indicating V the direction of the slight twistwhich the operator gives the conductor in removing it when stripping thesevered insulation therefrom, and

Fig. 8 is a view of the end of the conductor with the insulation removedtherefrom.

As shown .in the drawings, 10 is a frame or support for the mechanismprovided with a flanged base 11 spanning an opening 12 in a bench orother suitable supporting means 13 towhich it is secured. Extending fromthe base 11 and through the opening 12 of the bench 13 is a funnelshaped member 1 1 through which the stripped insulation mayfall and intoa suitable receptacle placed i thereunder, or if desired, the member 14may be connected. with a suitable exhaust system for drawing off thestripped insulation as it falls. The rear wall of the frame 10 isenlarged as indicated at 17 and above this portion is a sectionindicated at 18 provided on its inside face with a flat guide surface 19upon which rides a block 20. Passing through an opening 21 intheenlarged section 17 of the frame 11 is an opcrating rod 22 which maybe connected by a I link 24 to a'suitable foot treadle or otheroperating means, not shown. The operating rod 22 near its upper end isconnected to the Screw threaded into the opening 21 at the bottom of theframe 10 is a plug 26. Within the opening 21 and between the plug 26 anda bushing 27 hearing against the block 20 is a compression spring 28.The rod 22 is guided vertically 1n 1ts movement up and down by theplug26 and the bushing 27, and the block 20 pinned thereto is kept fromturning by its engagement with the flat guide surface 19. Projectingforward from the rear wall 18 is a member 31 against which the uppersurface of the block 20 bears. The rod 22 projects throu h the member"'31 and has screw threa ed onto its end adjusting nuts ,32 which bytheir spacingfrom the member 31 determine the movement downward of theblock 20 when the rod 22 is moved downward. Supported in the side wallsof the frame 10 and directly in line-with the upper and lower edges ofthe block 20 are supports connecting lead at 45.

or rails 33 upon which ride carriages 34, one for each of the burningblades 35. The carriages 34 are each equipped with a pin 38suitablysecured thereto at one end; the other end indicated at 39 isrectangular shaped and extends rearward into cam slots 40 formed in theblock 20. The cam slots 40 are so formed in the block that upon a slightmovement downward of the block 20 the rectangular shaped heads 39 willbe moved horizontally toward each other, thereby moving the carriages 34supporting the burning blades 35. upon the rails 33 in the samedirection. Mounted in front of each carriage 34 is ashoulderedinsulating block 41 preferably composed of asbestos lumber. Theelectrically heated blades or burning elements are wired in series. Thesupply leads are indicated at 43 and 44 and the The leads 43, 44 and 45are positioned on shoulders formed on the insulating blocks 41 and areconnected to the burning elements 35 by copper terminal blocks 46 towhich the elements 35 are secured by screws 47, 47. Spanning the ends ofthe copper terminal blocks 46 bearing against the insulating blocks 41of each element 35 is first an insulating cap 51 preferably madefrommica and next thereto is a steel cap 52. Passing through the steel cap52, mica cap 51 and the insulating block 41 and screw threaded into theblock 20 is a screw 53 for clamping the terminal block 46 in place onthe insulating block 41 with the ends of the leads 43, 44 and 45 clampedtherebetween. As indicated in Fig. 1, the elements 35 are slotted at 54where they are secured to the terminal blocks 46 'by the screws 47 tofacilitate the renewal of the elements in case they are burnt out. Theleads 43, 44 and 45 are preferably made from laminated copper stripformed into a suitable shape to allow for the free movement of theburning elements 35 when operated. The supply leads 43 and 44, asindicated in Figs. 1, 2 and 5, are formed to extend downward from thepoint where they are clamped to the terminal blocks 46 and then outwardand inward, forming U-shaped portions 57, thereby allowing for themovement of the burning elements 35 (see Fig. 5). After the U-shapedformation the leads are formed to pass rearward through an insulatingbushing 58 secured in the rear wall of the frame 10 but separated onefrom the other by a strip of insulation 59, after which they areconnected to the inain supply leads 60. and 61 housed in an auxiliarycasing 62 and insulated therefrom by a block 63 composed of somesuitable insulating material.

The main supply leads and\ 61 pass through the opening 12 in thebenchj13 and are connected to a suitable. electrical supply source witha rheostat included in the; circuit in order to control the heat of theelements 35. The connecting lead 45 is formed to extend upward from thepoints where it is clamped to the terminal blocks 46, then outward andthen inward to a point midway between the ends thereof. At this point itrests upon a fiber washer 64 and is suitably shaped to facilitate thefree movement of the burning elements 35 when operated. A

72 is covered with a face plate 73 provided with an opening 74 for theinsertion of a conductor 75 (see Figs. 2 and 6). The opening 74 issuitably formed to allow the operator to clearly View the operation.

In the operation of the mechanism the adjusting nuts 32 are firstadjusted to allow the necessary movement of the burning elements 35,which movement is determined from the thickness of the insulation on theconductor, the movement toward each other of the elements 35 being justsullicient to burn through the insulation on the conductor withoutharming the conductor itself. The circuit of the rheostat is then closedand the current adjusted for the desired amount of heat, which isreached when the elements are heated to a cherry red. The operator thentakes the conductor 75 and inserts it within the opening 74 in the faceplate 73 and between the elements 35 and thereafterthe operating rod 22is moved downward by a foot treadle or other suitable means. Themovement downward of the rod 22 causes the rectangular shaped heads '39to move toward each other in a horizontal direction through the camslots 40 formed in the block 20. This movement of the heads 39 which aresecured to the carriages 34 moves the burning elements toward each otherand into contact with the insulation upon the conductor 75. The operatorupon the elements engaging the conductor gives the conductora slighttwist (see Fig. 7) and withdraws it from between the elements 35. Thetwist burns a groove in the insulation upon the conductor and thewithdrawing movement severs and strips the insulation from the end ofthe conductor. Upon the. release of the operating rod 22 the spring'28returns the mechanism to its normal position.

Due to the construction of the mechanism heretofore described, thestripping operation may be so rapidly performed that the mechanism maybeused to remove the in sulation from cords having tinsel conductors woundaround cotton cores without burning the cotton cores, although'the outerinsulation is burned through and stripped from the conductor.

What is-claimed is 1. In a mechanism for removing the insulatingcovering from a conductor, a pair of non-rotating members, means formoving said members to engage the insulation on the conductor atdiametrically opposite points, and means for heating the edges of saidmembers that contact with the insulating covering to burn through saidcovering, said members constructed and arranged whereby the conductormay be rotated therebetween and moved longitudinally to strip thesevered portion from the conductor.

2. In a mechanism for removing the insulating covering from a conductor,a pair of non-rotating members, anelement detachably secured to each ofsaid members, said element constructed of a material which may be heatedto a red heat by the passage of an electric current therethrough, andmeans for moving said members in straight paths 'to bring the heatedportions thereof into contact with the insulating covering on theconductor to burn through the said covering. I

3. In a mechanism for removing the insulating covering from a conductor,burning elements oppositely disposed, j carriages therefor, rails uponwhich said carriages are adapted to move, means for moving saidcarriages from opposite directions to clamp a conductor between theburning elements carried thereby, and means for heating said burningelements.

4. In a mechanism for removing the insulating covering from a conductor,a pair of non-rotating members, means for moving said members instraight paths into contact with the insulating covering on theconductor, means for heating the edges .of said. members which come incontact with the insulating covering to burn through the said covering,and means for varying the extent of movement of said members to accom--modate conductors of different sizes.

5. In a machine for removing the insulating covering from a conductor, aplurality of non-rotating clamping jaws, means for heating the clampingedges thereof, means for, moving said jaws toward each other in straightpaths to clamp a conductor therebetween, and means adapted to beadjustedto vary the movement of said jaws toward each other whereby theclamping edges thereof may engage different sized conductors.

6. In a mechanism for removing the insulating covering from a conductor,a plurality ofnon-rotating members, means for moving said members intoengagement with the, insulating covering on the conductor,

means for heating the edges .of said members which contact with theinsulating covering to burn through the said covering, a housing aroundsaid members forming a chamher, said housing having .an opening inalignment with the meeting edges of said members, and a\ dischargepassage communicating with the chamber to receive the portion of thecovering that is stripped from the conductor.

7. In a mechanism for removing. the insulating covering from aconductor, a plurality of non-rotating members, spring means fornormally holding said members separated, cam mechanism for moving saidmembers in straight paths into engagement with the insulating coveringon the conductor, and means for heating the edges of said members whichcontact with the 'in. sulating covering on the conductor to burn throughthe said covering.

8. In a mechanism for removing the insulating covering from a conductor,a pair of non-rotating moving carriages, a burning element mounted oneach of said carriages for engaging the insulating covering on oppositesides thereof, operating means including a cam for moving saidcarriages, and means for varying the movement of said carriages wherebysaid burning elements may engage different size conductors.

9. In a mechanism for removing the insulating covering from a conductor,nonrotating movable carriages, burning elements, means for supportingsaid burning elements upon said carriages comprising terminal blocks,current leads for said blocks, insulating means between said terminalblocks and carriages, and means for clamping said leads to said terminalblocks and the whole to said carriages.

10. In a mechanism for removing the insulating covering from conductors,a pair of burning elements non-rotating movable carriages for saidelements, means for'supporting said elements upon said carriagescomprising a pair of terminal blocks for each of said burning elementsand positioned at-the ends thereof, current leads for said blocks, aninsulating block between each of said terminal blocks and its respectivecarriage, and clamping means intermediate each pair of terminal blocksadapted to clamp said current leads to said terminal blocks and thewhole to its respective carriage.

In witness whereof, we hereunto subscribe our names this 26th day ofOctober A. 1)., i

